It is well-known that in bicycles intended for racing there is a constant search for solutions to improve performance. In particular, for bicycles intended for speed races, such as typically a time trial, a good aerodynamic configuration of all of the components of the bicycle is particularly important. Moreover, a factor that is considered to improve performance is not just the efficiency of all of the controls but also their ease and safety of actuation, so that the cyclist is put in a position to be able to concentrate on the physical effort without hindrances due to difficulties in actuating the controls.
Recently, specialised handlebars for races have become well-established, which have two ends facing markedly forwards, which allow the cyclist to maintain a torso position greatly leaning forwards, which is aerodynamically efficient.
With these handlebars, specific actuation devices, both for the brakes and for the gearshifts, have also become well-established; these devices are commonly called bar-end since they are housed right at the ends of the handlebars, so that the cyclist can easily actuate them without having to change his position.
There are also known electric actuation devices for gearshifts, in which the cyclist must actuate—for each gearshift—a first switch to command upward gearshifting and a second switch for downward gearshifting. Typically, the first and the second switch are adjacent.
A bar-end type electric actuation device of the gearshift is described in EP A2 2105377. This device provides a body, which forms an ideal extension of the cylindrical tube of the handlebars, and a first and a second electric actuation element of the gearshift adjacent to and projecting laterally from the body. Since the two actuation elements are arranged adjacent to one another, they may be actuated accidentally, for example in the case of travel on uneven ground. This, of course, is undesirable during a sports competition. Secondarily, for example in the case in which the electric actuation elements of the gearshift face in opposite lateral directions of the body described in EP A2 2105377, in order to command upward gearshifting and downward gearshifting the cyclist must not only use two fingers, typically the thumb and the index finger, but he must also perform movements that can easily force him to release or at least alter his grip on the handlebars. All of this complicates the actuation of the gearshift, with consequent undesirable reduction of the ability to concentrate on the physical effort.
The Applicant has realised that it is possible to improve the overall efficiency of an actuation device of the gearshift of this type, by designing it specifically to allow each cyclist to take up the most suitable hand position, and to maintain the position substantially unchanged during the actuation of the device.